“We advise you to avoid the annual parades which occur in Northern Ireland during the months of April to August.

“These parades may turn violent with little warning.”

The advice reminded Australians to “exercise caution” when travelling to the United Kingdom.

A general warning on terrorism in the UK added: “We advise you to exercise caution and monitor developments that might affect your safety in the United Kingdom because of the risk of terrorist attack.”

The government’s advice noted that "two bombs were defused in County Down on 4 and 8 August 2010, and a car bomb exploded outside a police station".

Margaret Ritchie, Nationalist SDLP South Down MP, reacted with anger, saying the new advice was an “overreaction”.

She wrote to Bruce Davis, the Australian Ambassador in Dublin and John Dauth, the High Commissioner in London, inviting to visit Northern Ireland.

"The decision by the Australian government to warn its citizens about visiting Northern Ireland seems to be somewhat of an overreaction," she said.

"It is the stated aim of dissident republicans to destabilise the peace and this type of advice plays right into their hands."

Arlene Foster, the Northern Ireland Tourism Minister, said she would be raising the matter with the Foreign Office in London.

Niall Gibbons, chief executive of Tourism Ireland, which markets the island abroad, said the threat assessment had not changed and was the same level as the US, France and Germany.

"We will be taking the matter up with the ambassador in Dublin. It does not reflect a lot of hard work done on the ground to improve the perception of Northern Ireland as a tourist destination," he said.

Figures show around 50,000 Australians and New Zealanders visit Northern Ireland each year compared to more than 1.5m visitors from England, Scotland and Wales.

On Thursday night a viable device was discovered in Carrickfergus, County Antrim.

Other countries including New Zealand and the United States warn about rising dissident threats.

A spokesman for the Australian Consulate in London declined to comment, referring inquiries to Canberra.

A DFAT spokesman defended the new guidance saying the "overall level of the advice did not change".

"All Australian travel advisories, including our travel advice for the United Kingdom, are kept under constant review and updated promptly to reflect any new information or in response to changes in safety and security environments," he said.